1. Field of Endeavor
The present invention relates to a gap seal for radial sealing of a gap which extends axially and radially between two blades of a turbomachine which are adjacent in the circumferential direction.
2. Brief Description of the Related Art
In turbomachines, that is to say compressors, turbines and the like, blades are arranged adjacent to each other in the circumferential direction. In this case, gaps occur in the region of the blade roots, especially in the case of rotor blades which are arranged on the rotor side, which gaps extend in each case axially and radially between the blade roots of adjacent blades. In order to avoid the entry of hot gases into the gap, or in order to avoid the escape of cooling gas from the gap, it is necessary to seal this gap in the radial direction. For this purpose, in each two blades which are adjacent in the circumferential direction, it is basically possible to provide in each case an axially extending longitudinal slot, which is open towards the gap, on its respective blade root. A band-form or strip-form sealing element can then be inserted in these longitudinal slots, which lie in alignment opposite each other in the gap, in such a way that it engages with its longitudinal sides in the two longitudinal slots, and so bridges the gap.
With such gap seals, however, a residual gap can still exist on the end-face end of the sealing element. This can be attributed to manufacturing tolerances. Furthermore, this residual gap can be formed or enlarged due to thermal expansion effects during operation of the turbomachine.